1. Field of the Invention
The present invention relates to a control signal generating circuit generating a control signal used for an organic light emitting diode (OLED) display for signals such as a scan signal, a data signal or a light emitting signal.
2. Description of the Related Art
Various kinds of flat display devices that are capable of reducing detriments of cathode ray tubes (CRT), such as their heavy weight and large size, have been developed in recent years. Such flat display devices include liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), and organic light emitting diode OLED displays.
Among the above flat panel displays, the OLED display using an organic light emitting diode OLED generating light by a recombination of electrons and holes for the display of images has a fast response speed, is driven with low power consumption, and has excellent luminous efficiency, luminance, and viewing angle such that it has been spotlighted.
Generally, the organic light emitting diode OLED display is classified into a passive matrix OLED (PMOLED) and an active matrix OLED (AMOLED) according to a driving method of the organic light emitting diode OLED.
Of them, the active matrix in which unit pixels are selectively lit is primarily used in terms of resolution, contrast, and operation speed.
A predetermined time is required when increasing and decreasing a control signal controlling a display device such as the AMOLED. Conventionally, the rising period (Tr) and the falling period (Tf) of the various input signals of the AMOLED (for example, a scan signal, a data signal, a light emitting signal) are controlled by a time constant such that they are generally designed to be increased and decreased while drawing the same curved line.
However, when there is a short circuit in the rising period or the falling period in the driving method of the circuit of the AMOLED, a very large current flows into the AMOLED such that the element characteristic and reliability may be deteriorated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.